diff options
Diffstat (limited to 'sysdeps/powerpc/fpu/e_hypotf.c')
| -rw-r--r-- | sysdeps/powerpc/fpu/e_hypotf.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/sysdeps/powerpc/fpu/e_hypotf.c b/sysdeps/powerpc/fpu/e_hypotf.c new file mode 100644 index 0000000000..3e6c597cc9 --- /dev/null +++ b/sysdeps/powerpc/fpu/e_hypotf.c @@ -0,0 +1,118 @@ +/* Pythagorean addition using floats + Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011 + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "math.h" +#include "math_private.h" + + +static const float two30 = 1.0737418e09; +static const float two50 = 1.1259000e15; +static const float two60 = 1.1529221e18; +static const float two126 = 8.5070592e+37; +static const float twoM50 = 8.8817842e-16; +static const float twoM60 = 6.7762644e-21; +static const float pdnum = 1.1754939e-38; + + +/* __ieee754_hypotf(x,y) + * + * This a FP only version without any FP->INT conversion. + * It is similar to default C version, making appropriates + * overflow and underflows checks as well scaling when it + * is needed. + */ + +#ifdef _ARCH_PWR7 +/* POWER7 isinf and isnan optimizations are fast. */ +# define TEST_INF_NAN(x, y) \ + if (isinff(x) || isinff(y)) \ + return INFINITY; \ + if (isnanf(x) || isnanf(y)) \ + return NAN; +# else +/* For POWER6 and below isinf/isnan triggers LHS and PLT calls are + * costly (especially for POWER6). */ +# define GET_TWO_FLOAT_WORD(f1,f2,i1,i2) \ + do { \ + ieee_float_shape_type gf_u1; \ + ieee_float_shape_type gf_u2; \ + gf_u1.value = (f1); \ + gf_u2.value = (f2); \ + (i1) = gf_u1.word; \ + (i2) = gf_u2.word; \ + } while (0) + +# define TEST_INF_NAN(x, y) \ + do { \ + int32_t hx, hy; \ + GET_TWO_FLOAT_WORD(x, y, hx, hy); \ + if (hy > hx) { \ + uint32_t ht = hx; hx = hy; hy = ht; \ + } \ + if (hx >= 0x7f800000) { \ + if (hx == 0x7f800000 || hy == 0x7f800000) \ + return INFINITY; \ + return NAN; \ + } \ + } while (0) +#endif + + +float +__ieee754_hypotf (float x, float y) +{ + x = fabsf (x); + y = fabsf (y); + + TEST_INF_NAN (x, y); + + if (y > x) + { + float t = y; + y = x; + x = t; + } + if (y == 0.0 || (x / y) > two30) + { + return x + y; + } + if (x > two50) + { + x *= twoM60; + y *= twoM60; + return sqrtf (x * x + y * y) / twoM60; + } + if (y < twoM50) + { + if (y <= pdnum) + { + x *= two126; + y *= two126; + return sqrtf (x * x + y * y) / two126; + } + else + { + x *= two60; + y *= two60; + return sqrtf (x * x + y * y) / two60; + } + } + return sqrtf (x * x + y * y); +} |